This invention relates to joints for connecting tubular structural members, such as supporting frames and beams for vehicle bodies, and more particularly to a hollow joint structure providing efficient interior stiffening of the connecting joint for tubular members.
It is known in the art relating to tubular frame structures to connect the tubular members at angularly intersecting joints using various forms of stiffening including overlapping elements, as well internal and external gussets or stiffener plates. With an increasing reliance on hydroformed tubular frame members joined together for supporting the body structure and other members in automotive vehicles, there is often limited room for the application of external braces or gussets. Overlapping joint constructions may be used but often provide a less than desired strength in torsional or bending modes. Internal gussets have been proposed but are often difficult to apply. Thus, a need for a more efficient joint construction providing increased strength with a minimum of additional mass or assembly difficulty is desired.
The present invention provides a hollow joint construction between tubular members of a frame structure that is particularly desirable for hydroformed members, although applicable to tubular structures of various types.
A primary feature of a frame structure incorporating the invention is that the joint is defined by a hollow box section including sides that form continuous extensions through the joint of preferably all the sides of the tubular members that are being joined. Also, the edges of the joint sides are welded or integrally connected to one another and are likewise connected with the sides of the tubular members or elements that are joined by the joint.
Where appropriate, less desirable alternative constructions formed according to the invention may omit one of the interior extension walls of the joint or may have some of the edges of the joint sides disconnected from adjacent tubular members in order to simplify manufacturing while still providing some of the advantages of the fully connected and fully strengthened idealized joint arrangement.
These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.